Stormtroopers aren't designed to have a standoff with tactical assault. They're designed to catch squads moving somewhere and ambush them with tac assault, taking minimal damage themselves while maximizing their own.
Consider joining Whiteflashreborn's discord so people can see changes and post feedback and replays there for you.
And the Brummbar wreck can be salvaged by UKF Tac Support engineers. When I called them in, during game 2, a flare illuminated the wreck, meaning it can be salvaged by them. Have a look at it.